bloom — GFX2D post op

• 資料種類:rgb → rgb

• 呼叫:import gfx2d; gfx2d.bloom(rgb, threshold=0.8, sigma=4.0, intensity=0.6)(或 opsgfx2d.get("bloom"))

用法

讓影像的明亮部分向周圍滲出。

> 以下的詳細說明為原文 —— 摘要與標題已翻譯。

The classical three steps: isolate what is above `threshold`, blur it by a

Gaussian of `sigma, add intensity` times the result back, clip.

A *linear-light* operator: light spreading in a lens adds radiance. Running

it on sRGB-encoded values makes the halo too strong in the mid-tones —

`srgb_to_linear first, linear_to_srgb` after.

Exact identities: `intensity=0 and threshold >= 1` both return the

input bit for bit, and a black image stays black.

The added energy is *not* conserved by the clip at the end. The suite

measures both halves: on a centred bright blob the Gaussian preserves the

bright mass to 5.0e-16 relative, so everything lost after that is the

clip — on a random scene with a saturated square, 2.69 % of the pixels clip

and 1.65 % of the total energy is thrown away, and neither number is

returned to the caller.

參考(範例資料・文獻)

• 範例資料目錄(下載 URL / 授權) —— 2-D 用 skimage.data(BSD/公有領域)加合成圖,3-D 給出真實資料源(Stanford/PDS 等)的下載 URL。

• 運算子來歷與參考文獻 —— 該運算子族所依據的研究/方法出處。

• 演算法的正典(作者・年份)與用途見上面的族使用指南。

可執行的範例(實際呼叫該運算子並已驗證的樣例)

• gfx2d_scene — py -3.11 examples/gfx2d_scene.py

型別可銜接的下一個運算子(可接受 rgb 作為輸入)

srgb_to_linear · linear_to_srgb · blend_mode · light_mask · normal_map_decode · vignette · chromatic_aberration · film_grain

同類別(post)

vignette · chromatic_aberration · film_grain · color_lut · color_grade · dither · palette_quantize

*Provenance: gfx2d.py — GFX2D 運算子登記表。本條目由 tools/opdocs.py md 自動產生(請勿手動編輯)。*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.